Allen Morgan, a leading expert on drug use, trials and trafficking in the UK, admits he's deeply concerned about legal highs.

He told Daily Star Online in an exclusive interview: "We understand the effects of drugs like cannabis but some of these legal highs are so new there's no way of knowing what the long term effects could be.

"With drugs such as heroin at least we understand them and can treat people in the correct way. That's not the case with legal highs.

"People assume that because they're legal they're safe. That clearly isn't the case and people may react to them in very different ways.

"There's very little known about these substances. That's what's worrying.

"There is little control over manufacture or content so people could buy two of the same branded products and both have completely different substances inside."

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WEED: Morgan says the danger in legal highs, unlike illegal drugs, is fear of the unknown

Black Mamba, like "spice", is a chemical made to act like the active part of cannabis and it certainly makes people do strange things.